Subject: Astronomy and Origins
Organization: UTexas Mail-to-News Gateway
From: jmeritt@mental.mitre.org
Message-ID: <9306231608.AA03165@asia.mitre.org>
Newsgroups: talk.origins
Topics:
} - Helmholtz's contraction theory says the sun is < 20,000,000 years.
} - Sun is shrinking by ~5 feet per hour.
} - Lunar dust--only 1 to 3 inches, not 54 feet.
} - Deterioration of earth's magnetic field
} - Atmospheric helium should have built up
} - Receding moon would have been touching earth
} - All comets would have disintegrated after 10,000 years.
} - galaxy formation.
) - biblical cosmology
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} - Helmholtz's contraction theory says the sun is < 20,000,000 years.
This (suns energy comes from contraction) is decades old and discarded soon
after the discovery of radioactivity. See the Scientific American article
from August 1989. The German physicst Hermann von Helmholtz formulated
this concept around 1869. It has been soundly rebuffed in the last
100 years.
- The guy who thought that we were detecting 0 (zero) solar neutrinos,
thus proving his theory that the sun was shining due to the
gravitational energy released as it shrank.
(they are there, and have been detected)
} - Sun is shrinking by ~5 feet per hour.
}i.e losing 0.01% per year. 6,000 creation = ~6% shrinkage, but 20,000,000
}years ago the sun touched the earth and 100,000 years ago the sun was twice
}as large (making life impossible).
I am interested in how you decide that this is a steady-state system?
A "Sun" that large could not possibly have this solar system.
A brief discussion of this is found in "Looking Inside the Sun", ASTRONOMY,
March 1989.
Analysis of historical records of eclipses and transits give varying
numbers. One result gives 2.25 arcseconds per century, similar to the
above figure. Another result gives an upper limit of 0.3 arcsecond per
century, but is also consistent with no shrinkage. Two more historical
analyses indicate that the sun was a bit larger a century ago than
today. Current measurements indicate that the sun is not now shrinking.
The long term stability of the size of the sun remains unknown.
} - Lunar dust--only 1 to 3 inches, not 54 feet.
The calculation you refer to is given by Henry Morris on pp.
151-153 of _Scientific Creationism_. It is based on a grossly erroneous
figure of 14 million tons of meteoritic dust per year, quoted by Petterson
in 1960. Morris misinterpreted Petterson's article. Petterson published a
figure of 15 (not 14) million tons per year as an _upper limit_. In
other words, Petterson said that the value is _not more than_ 15 million
tons per year. He was not able to measure an actual value. Morris
erroneously chose to interpret it to mean it was _equal_ to 14
million tons per year. Accurate values were measured in the late
1960's. The actual value is much lower than 15 million tons per year.
Dalrymple gives the value of 22,000 tons per year, nearly 700 times
smaller than your figure. That changes your 54 foot figure into about
2 cm, which is quite consistent with the amount of surface soil the
astronauts found on the Moon (it was considerably more than 1-2 mm).
My copy of "Everyman's Astronomy" indicates that the earth collects
about 9000 kg per day from meteors of visual magnitude 5.0 or brighter.
Assuming a typical rock density of 3 g/cc, this corresponds to an
accumulation rate of one inch per 10 billion years. Unfortunately no
data is presented for fainter meteors. I wouldn't be surprised to find
that the actual rate is one or two orders of magnitude higher, but "1
inch in 8000 years" is off by six orders of magnitude.
A dust accumulation rate of "one inch per 8000 years" should should
create a spectacular yearround meteor shower, and cause severe pitting
of the space shuttle windshields in just a single orbit. My quick estimates
give values far higher than have been actually observed.
} - Deterioration of earth's magnetic field, at present rates, implies an
} excessive field 10,000 years ago.
> Decay of Earth's Magnetic Field - Result of research by Thomas Barnes
> during his tenure as Physics Professor at UTEP. Published in _Origin and
> Destiny of Earth's Magnetic Field_, 1973. Barnes notes the measured
> values over the last 150 years and models according to uniformitarian
> principles.
The decay is not a steady state. In fact, there is considerable evidence
for reversals. The atlantic ocean floor as it spreads shown the weakening
- reversing - strengthening recorded in its stone as the contenents
spread from the mid-atlantic ridge.
The field is expected to reverse sometime in the next few thousand
years. A time scale on page 78 shows the reversals over the past 170
million years, as deduced from the magnetic patterns in oceanic crust.
I counted about 200 reversals on the chart.
Briefly, Barnes took approximately 150 years of data on the Earth's
dipole magnetic field and extrapolated it backwards to about 10000
years Before Present (B.P.). He stated that the field 10,000 years ago
would, on this calculation, have been as strong as that of a magnetic
star, and stated (correctly) that this was absurd. However, there
are four fatal flaws in his analysis.
In the first place, Barnes studied only the *dipole* component of the
Earth's magnetic field, In fact, the very same data that Barnes used
show that the *nondipole* component of the field *increased* during
the same period of time, almost exactly cancelling the decrease in
the dipole field that Barnes calculated (D. Brent Dalrymple, U. S.
Geological Survey, Menlo Park CA, in *Reviews of 31 Creationist Books*).
This alone is sufficient to destroy the basis of his work.
The second failure of Barnes' study was the idea that one can take data
from a short period of time and simply extrapolate it backwards to obtain
a reliable estimate at a time remotely removed from the data. Anyone
competent in analyzing scientific data knows that extrapolations are good
only for a relatively short period of time, if at all, and that the further
away from the actual data one goes, the less reliable it becomes. Barnes
extrapolated 150 years' worth of data back 10,000 years! In real life,
one would be surprised if extrapolation of these data more than a few
hundred years back were accurate.
The third failure of Barnes' study was the mathematical model he
chose. He decided to fit the data to an exponential. The data fit
a straight line just as well (see Figure 1 of Stephen G. Brush's
article in *Scientists Confront Creationism*), but a straight line
would have given a much older age for the Earth than the 10,000 years
that Barnes, because of his Biblical literalism, wishes to promote.
The fourth failure of Barnes' study was his failure to consider any other
evidence than the 150 years worth of data from geomagnetic observatories
that he used. There exists, in paleomagnetic data, a long record of
the Earth's magnetic dipole strength (extending backwards for millions
of years). The data are in agreement with the observatory data Barnes
used over their common intersection, but they differ drastically from
Barnes' extrapolation when one goes further back in time.
} - Atmospheric helium should have built up more from U decay.
This statement is false. It falls precisely within predicted limits.
Please read:
Calculations on the Composition of the terrestrial Planets
Reynolds & Summers, Journal of Geophysical Research vol 74, no 10
May 15, 1969 p 2494
The formation of the Earth from Planetesimals
Wetherill, Scientific American June 1981
Cloud, Preston E., Jr., "Atmospheric and Hydrospheric Evolution on
the Primitive Earth", Science 160, (17 May 1968), pp 729 - 736
Mart, Michael H, "The Effect of a Planet's Size on the Evolution of
its Atmosphere", published in some conference or another; I
got a copy from the author. (ave Allen )
Our Evolving Atmosphere
Is Anyone There? by Isacc Asimov
The Evolution of the Atmosphere of the Earth
Hart, Icarus, 33, 23-39, 1978
Evolution of the Atmosphere and Oceans
Holland, Lazar & McCaffery, Nature vol 320, 6 mar 1986
Heat and Helium in the Earth
O'Nions & Oxburgh, Nature, vol 306, 1 Dec 1983
The Atmosphere
Ingersoll, Scientific American, Sept 1983
} - Receding moon would have been touching earth 2 billion years ago.
Check up on your orbital dynamics...
Assumes a steady rate of recession. Assumes the moon wasn't captured less
than 2 billion years ago.
} - All comets would have disintegrated after 10,000 years.
Jupiter and Saturn wreak havoc to the comet orbits. Some long-period
comets are perturbed into short period orbits, others are permanently
ejected. Comets are believed to have a short lifetime after being
perturbed to short periods.
Actually, the Oort cometary cloud hypothesis (published by Jan H. Oort in
1950) was originally proposed in order to explain "the rate of appearance
of long-period comets" (i.e. there are a lot of them). It really didn't
have anything to do with the age of short-period comets (which the note
above refers to). [Long-period > 200 yrs, short-period < 200 yrs.]
The problem that is referred to by the creationist here is that the short-
period comets *have not occupied their present orbits* for very long (in
astronomical terms). Each time a comet passes close to the sun, some of
its matter is driven off into space by the sun's energy (forming its "tail").
"Short-period" comets are believed by astronomers to have a lifetime of
only a few thousand years, because after that all of their "tail-producing"
matter would be used up (indeed, astronomers have noted comets to "vanish";
the remaining material only makes its presence known upon entering the
Earth's atmosphere; this is likely the origin of meteoroid swarms.)
However, the fact that a comet cannot have occupied its present orbit for
very long does not automatically imply that it is young. The Oort hypothesis
does explain this problem as well, in that long-period comets -- if frequent
enough -- will be moved into short-period orbits by a relatively near approach
to a planet (comet loses momentum, planet gains it, comet is now in a vastly
shorter orbit, planet is now in a very slightly longer orbit).
In fact, of the short-period comets, roughly half orbit pretty much between
the sun and jupiter, leading astronomers to belive that jupiter "captured"
them into their current orbits. (Statistically, we would expect the largest
planet -- the best "capturer" -- to have captured the most short-period
comets).
Finally, nobody really knows about the Oort cloud. Astronomers like the
way it explains the frequency of long-period comets, and there is much
support for it amongst them. It apparently also explains the youth of the
short-period comets, quite nicely. However, until we see a comet get sucked
into a short-period orbit (apparently this must happen every 100 years or
so), or until we send something out to 10,000 A.U., Oort's proposal remains
a hypothesis. (Conclusion: it was *not* cooked up to explain young short-
period comets; this is something of a "fringe benefit". But we aren't very
sure that it's true, either.)
[From Strahler, "Science and Earth History", New York:Prometheus, 1987; p. 143]
}An important element in the argument against the evolutionary universe
}is the failure of conventional cosomology to solve the problem of
}galaxy formation.
With the development of GUT, we see galaxy formation is no longer a problem
at all but simply one more natural phenomenon with a perfectly natural
explaination.
James S. Trefil
_The Moment of Creation_
) - biblical cosmology
And in several places in the Bible, the sky is referred to as
a vault, with the stars stuck on it. Genesis 1 refers to water above
this vault (an idea no doubt borrowed from the Babylonian cosmology,
which pictured the Earth as a flat disk inside a cosmic bubble in a
cosmic sea). The Book of Revelation states that the stars will someday
fall out of the sky like figs from a tree. The Bible says little about
the shape of the Earth, referring in one place to the "circle" of the
Earth (a disk shape), and in another place to the "four corners" of
the Earth (a rectangular surface shape). In one of the Gospels, the
Devil tempted Jesus by taking him up a mountain where he could see
"all the kingdoms of the world" (no further info on this remarkable
mountain). This would only be possible if the Earth was flat.
The Bible does indicate more clearly, however, that the Earth
is motionless. Witness Joshua's telling the Sun (and not the Earth) to
stop just so he could win one of his battles, and some of the Psalms
that state that the Earth is motionless. The Joshua story can be used
to find a Biblical estimate of the distances of the Sun and the Moon
from the Earth. Since we are told that the Sun was stopped to
illuminate the Valley of Gibeon, and the Moon to illuminate the Valley
of Aijalon, we conclude that either one of them would have been
insufficient for both -- and that requires that the Sun be low when
viewed from the Moon's valley, as it were, and vice versa. This
implies that the distances to the Sun and the Moon are comparable to
the distance between the Valleys of Gibeon and Aijalon, which is about
10 mi.
In all fairness to the writers of the Bible, none of this
cosmology is any worse than the cosmological pictures developed by
surrounding peoples, with one exception. Ancient Greek
proto-scientists (if that is the proper word) were, without any modern
technology, able to establish that the Earth was approximately
spherical, and were able to work out the approximate size of the Earth
and the distance to the Moon. The distance to the Sun was more
difficult, and almost all were agreed that the Sun moved around the
Earth. But this knowledge was gained only after the Old Testament was
written, though some of the writers of the New Testament may have
learned of Aristotle's demonstration of the approximate sphericity of
the Earth three centuries ago. The Greeks had data which anyone else
living before modern times could collect, but they put the pieces
together in the right fashion, and, for some reason, there is no hint
of that in the Bible.